Currently, measuring power usage loads and fluctuations for residential and commercial environments is accomplished via Current Transformer (CT) clamp technology. Products such as smart meters and other energy monitoring products such as the TED 5000 series available from Energy, Inc. of Charleston, S.C., the Neurio Sensor available from Neurio Technology, Inc. of Vancouver, BC, Canada and the EHEM1 Home Electricity Monitor available from Eyedro Green Solutions, Inc. of Kitchener, ON, Canada utilize CT technology because it is relatively straightforward to discern power usage, as the magnetic fields from a single wire which a CT clamp surrounds have a simple physical relationship to the electrical current present in the wire. Such products typically determine the power by multiplying the instantaneous current sensed by each CT clamp by the time-varying voltage. By integrating this instantaneous power over a time period such as one second, the total power used during that one second time period can be calculated.
However, the installation of CT clamps is difficult and dangerous because the procedure requires removing of the outside protective panel of the electrical breaker box and further requires the installer to come in close contact with high-powered electrical lines that can cause personal physical harm or even death. This sort of installation is not practical for a homeowner to complete; most homeowners would not be comfortable performing the installation and instead opt to hire an electrical contractor to perform the work at a significant expense. Also, CT clamp installations take a significant amount of time due to the labor involved in removing fuse box covers, carefully connecting CT clamps and associated wires. Even an installation by a professional electrician can take thirty or more minutes.